The invention relates to an organic electroluminescent component with a transparent substrate, a first transparent electrode, an organic electroluminescent layer, and a second electrode.
Electroluminescent components built up from organic layers are of major importance because they can be manufactured in the form of large-area displays which can be operated at low voltages and which have a short response time and a low weight. They can also be manufactured in the form of flexible foils which are more widely applicable than traditional electroluminescent components made from inorganic semiconductor material. Fields of application for organic electroluminescent components accordingly are displays of all kinds, in particular also flat monitors and picture screens. The components are suitable for use as light sources in airplanes and spaceships because of their low weight. A further possibility is for these components to be used as laser diodes.
Traditional organic electroluminescent components usually have a layer structure comprising several separate layers. An organic electroluminescent component is known, for example, from U.S. Pat. No. 4,720,432 and comprises in that order an anode, an organic hole injecting and transporting zone, an organic electron injecting and transporting zone, and a cathode, and which is characterized in that the hole injecting and transporting zone comprises a layer which is in contact with the anode and which contains a hole injecting porphyrinic compound, and furthermore comprises a layer which contains a hole transporting aromatic tertiary amine and which lies between the hole injecting layer and the electron injecting and transporting zone.
Such multiple combinations of layers with charge injecting and charge transporting organic materials necessarily have many interfaces. The transition voltages at the interfaces lead to an undesirable increase in the operating voltage, a reduction in the current density, and a reduction in the brightness of the electroluminescent component.
It is accordingly an object of the present invention to provide an organic electroluminescent component which has a simple layer structure.